Hydraulic fracturing (also known as fracking) is a well-stimulation process that utilizes pressurized liquids to fracture rock formations. Pumps and other equipment used for hydraulic fracturing typically operate at the surface of the well site. The equipment may operate semi-continuously, until refueling is needed, at which time the equipment may be shutdown for refueling. Shut-downs are costly and reduce efficiency. More preferably, to avoid shut-downs fuel is replenished in a hot-refueling operation while the equipment continues to run. This permits fracking operations to proceed fully continuously; however, hot-refueling can be difficult to reliably sustain for the duration of the fracking operation.